5 Elementary procedures between TSN AF and DS-TT

24.5193GPP5G System (5GS)Release 16Stage 3Time-Sensitive Networking (TSN) Application Function (AF) to Device-Side TSN Translator (DS-TT) and Network-Side TSN Translator (NW-TT) protocol aspectsTS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

5.1 General

The UE and the network may support transfer of standardized and deployment-specific Ethernet port management information between a time-sensitive networking (TSN) AF and the DS-TT at the UE, to manage the Ethernet port used at the DS-TT for a PDU session of "Ethernet" PDU session type. The Ethernet port management messages are included in a Port management information container IE and transported using the UE-requested PDU session establishment procedure, the network-requested PDU session modification procedure or the UE-requested PDU session modification procedure as specified in 3GPP TS 24.501 [5] clauses 6.4.1.2, 6.3.2 and 6.4.2.

5.2 Procedures

5.2.1 Network-requested Ethernet port management procedure

5.2.1.1 General

The purpose of the network-requested Ethernet port management procedure is to enable the TSN AF to:

a) obtain the list of port management parameters supported by the DS-TT;

b) obtain the current values of port management parameters at the DS-TT Ethernet port;

c) set the values of port management parameters at the DS-TT Ethernet port;

d) subscribe to be notified by the DS-TT if the values of certain port management parameters change at the DS-TT Ethernet port;

e) unsubscribe to be notified by the DS-TT for one or more port management parameters; or

f) delete a port management parameter-entry at the DS-TT Ethernet port.

5.2.1.2 Network-requested Ethernet port management procedure initiation

In order to initiate the network-requested Ethernet port management procedure, the TSN AF shall:

a) encode the information about the port management parameters values to be read, the port management parameters values to be set, the port management parameters changes to (un)subscribe to, the port management parameter-entry to be deleted and whether the TSN AF requests the list of port management parameters supported by the DS-TT in an Ethernet port management list IE as specified in clause 9.2 and include it in a MANAGE ETHERNET PORT COMMAND message;

c) send the MANAGE ETHERNET PORT COMMAND message to the UE via the PCF and the SMF as specified in 3GPP TS 23.502 [3]; and

d) start timer T100 (see example in figure 5.2.1.2.1).

Figure 5.2.1.2.1: Network-requested Ethernet port management procedure

5.2.1.3 Network-requested Ethernet port management procedure completion

Upon receipt of the MANAGE ETHERNET PORT COMMAND message, for each operation included in the Ethernet port management list IE, the DS-TT shall:

a) if the operation code is "get capabilities", include the list of Ethernet port management parameters supported by the DS-TT in the Ethernet port management capability IE of the MANAGE ETHERNET PORT COMPLETE message;

b) if the operation code is "read parameter", attempt to read the value of the parameter at the DS-TT Ethernet port, and:

1) if the value of the parameter at the DS-TT Ethernet port is read successfully, include the parameter and its current value in the Ethernet port status IE of the MANAGE ETHERNET PORT COMPLETE message; and

2) if the value of the parameter at the DS-TT Ethernet port was not read successfully, include the parameter and associated Ethernet port management service cause value in the Ethernet port status IE of the MANAGE ETHERNET PORT COMPLETE message;

c) if the operation code is "set parameter", attempt to set the value of the parameter at the DS-TT Ethernet port to the value specified in the operation, and:

1) if the value of the parameter at the DS-TT Ethernet port is set successfully, include the parameter and its current value in the Ethernet port update result IE of the MANAGE ETHERNET PORT COMPLETE message; and

2) if the value of the parameter at the DS-TT Ethernet port was not set successfully, include the parameter and associated Ethernet port management service cause value in the Ethernet port update result IE of the MANAGE ETHERNET PORT COMPLETE message;

d) if the operation code is "subscribe-notify for parameter", store the request from the TSN AF to be notified of changes in the value of the corresponding parameter;

e) if the operation code is "unsubscribe for parameter", delete the stored request from the TSN AF to be notified of changes in the value of the corresponding parameter, if any;

f) if the operation code is "delete parameter-entry", attempt to delete the referred parameter-entry of the parameter at the DS-TT Ethernet port; and

1) if the parameter-entry of the parameter at the DS-TT Ethernet port is deleted successfully, include the parameter and its current value in the Ethernet port update result IE of the MANAGE ETHERNET PORT COMPLETE message; and

2) if the parameter-entry of the parameter at the DS-TT Ethernet port was not deleted successfully, include the parameter and associated Ethernet port management service cause value in the Ethernet port update result IE of the MANAGE ETHERNET PORT COMPLETE message; and

g) send the MANAGE ETHERNET PORT COMPLETE to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

5.2.1.4 Abnormal cases on the network side

The following abnormal cases can be identified:

a) T100 expired.

The TSN AF shall, on the first expiry of the timer T100, retransmit the MANAGE ETHERNET PORT COMMAND message and shall reset and start timer T100. This retransmission is repeated four times, i.e. on the fifth expiry of timer T100, the TSN AF shall abort the procedure.

5.2.1.5 Abnormal cases in the DS-TT

The following abnormal cases can be identified:

a) Transmission failure of the MANAGE ETHERNET PORT COMPLETE message indication from lower layers.

The DS-TT shall not diagnose an error and consider the network-initiated Ethernet port management procedure complete.

NOTE: Considering the network-initiated Ethernet port management procedure complete as a result of this abnormal case does not cause the DS-TT to revert the execution of the operations included in the MANAGE ETHERNET PORT COMMAND message.

5.2.2 DS-TT-initiated Ethernet port management procedure

5.2.2.1 General

The purpose of the DS-TT-initiated Ethernet port management procedure is to notify the TSN AF of one or more changes in the value of Ethernet port management parameters for which the TSN AF had requested to be notified of changes via the network-initiated Ethernet port management procedure.

5.2.2.2 DS-TT-initiated Ethernet port management procedure initiation

In order to initiate the DS-TT-initiated Ethernet port management procedure, the DS-TT shall create an ETHERNET PORT MANAGEMENT NOTIFY message and shall:

a) include the Ethernet port management parameters to be reported to the TSN AF with their current value in the Ethernet port status IE of the ETHERNET PORT MANAGEMENT NOTIFY message;

b) start timer T200; and

c) send the ETHERNET PORT MANAGEMENT NOTIFY message to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

Figure 5.2.2.2.1: DS-TT-initiated Ethernet port management procedure

5.2.2.3 DS-TT-initiated Ethernet port management procedure accepted by the TSN AF

Upon receipt of the ETHERNET PORT MANAGEMENT NOTIFY message, the TSN AF shall:

a) create a MANAGE ETHERNET PORT MANAGEMENT NOTIFY ACK message; and

b) send the MANAGE ETHERNET PORT MANAGEMENT NOTIFY ACK message to the UE via the PCF and the SMF as specified in 3GPP TS 23.502 [3].

5.2.2.4 DS-TT-initiated Ethernet port management procedure completion

Upon receipt of the ETHERNET PORT MANAGEMENT NOTIFY ACK message, the DS-TT shall:

a) stop timer T200;

b) create an ETHERNET PORT MANAGEMENT NOTIFY COMPLETE message; and

c) send the ETHERNET PORT MANAGEMENT NOTIFY COMPLETE message to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

5.2.2.5 Abnormal cases on the network side

The following abnormal cases can be identified:

a) Transmission failure of the ETHERNET PORT MANAGEMENT NOTIFY ACK indication from lower layers.

The TSN AF shall not diagnose an error and consider the DS-TT-initiated Ethernet port management procedure complete.

5.2.2.6 Abnormal cases in the DS-TT

The following abnormal cases can be identified:

a) T200 expired.

The DS-TT shall, on the first expiry of the timer T200, retransmit the ETHERNET PORT MANAGEMENT NOTIFY message and shall reset and start timer T200. This retransmission is repeated four times, i.e. on the fifth expiry of timer T200, the DS-TT shall abort the procedure.

b) Transmission failure of the ETHERNET PORT MANAGEMENT NOTIFY COMPLETE message indication from lower layers.

The DS-TT shall not diagnose an error and consider the DS-TT-initiated Ethernet port management procedure complete.

5.2.3 DS-TT-initiated Ethernet port management capability procedure

5.2.3.1 General

The purpose of the DS-TT-initiated Ethernet port management capability procedure is to provide the DS-TT supported Ethernet port management capabilities to the TSN AF during PDU session establishment as specified in 3GPP TS 23.502 [3].

5.2.3.2 DS-TT-initiated Ethernet port management capability procedure

In order to initiate the DS-TT-initiated Ethernet port management capability procedure, the DS-TT shall create an ETHERNET PORT MANAGEMENT CAPABILITY message and shall:

a) include the DS-TT Ethernet port management capabilities in the Ethernet port management capability IE of the ETHERNET PORT MANAGEMENT CAPABILITY message; and

b) send the ETHERNET PORT MANAGEMENT CAPABILITY message to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

Figure 5.2.3.2.1: DS-TT-initiated Ethernet port management capability procedure